Binary data utility
Minecraft NBT Editor Online — Edit .dat & Nested Tags
Open a file, change its typed values, and save valid binary NBT. Format detection is automatic and the file never leaves your device.
Edit Java, Bedrock, and generic NBT files
Minecraft uses Named Binary Tag data for player inventories, world settings, entities, structures, and schematics. This editor reads the binary file directly and exposes each byte, short, integer, long, float, double, string, list, compound, and typed array without flattening those types into ordinary JSON.
You can use it with Java Edition files such as level.dat, player .dat files, structures, Sponge schematics, and Litematica schematics. It also understands standalone Bedrock little-endian NBT, .mcstructure files, and varint NBT. Files from other games or tools can work when they use a standard NBT byte order and compression format.
Saving retains the detected root tag, tag names, numeric types, endianness, and compression. Signed 64-bit longs remain exact rather than being rounded by JavaScript. The generated binary is parsed again before download so a failed round trip cannot silently produce a corrupted file.
What it opens
Detection uses the bytes inside the file, not a fixed extension list. That also makes the editor useful for NBT-based tools and games outside Minecraft.
Java Edition
- level.dat and playerdata
- .nbt structures
- .schematic and .schem
- .litematic
Bedrock Edition
- Standalone level.dat
- .mcstructure
- Little-endian NBT
- Varint network NBT
Generic NBT
- Any named root tag
- Unknown file extensions
- gzip, zlib, or raw
- Big or little endian
Local by design
Parsing, editing, compression, and saving happen in your browser. There is no upload endpoint and no account requirement.
Know the boundary
NBT editing is not Java-to-Bedrock conversion. Complete Bedrock LevelDB worlds and Java region.mcacontainers need dedicated database or region tools. Always keep the original file.
Format notes
- Are 64-bit longs safe?
- Yes. Longs are edited as decimal strings internally, avoiding JavaScript number precision loss.
- Does saving change the format?
- No. The detected byte order, compression, root name, tag types, and Bedrock header are retained.
- What happens before download?
- The generated bytes are parsed again and compared with the edited typed tree. Failed verification blocks the download.
- Why will some world files not open?
- Some files are containers around NBT rather than NBT streams themselves. Region and LevelDB files are the common examples.